Android上的LocationManager API似乎对一个只需要偶尔粗略估计用户位置的应用程序来说有点麻烦。

我正在开发的应用程序本身并不是一个定位应用程序,但它确实需要获取用户的位置,以便显示附近企业的列表。它不需要担心用户是否在移动或类似的事情。

以下是我想做的:

向用户显示附近位置的列表。预加载用户的位置,以便在“活动X”中需要它时,它将可用。我并不特别关心更新的准确性或频率。只要不太远,只要抓住一个位置就足够了。也许如果我想变得更漂亮,我会每隔几分钟左右更新一次位置,但这不是一个很大的优先事项。适用于任何具有GPS或网络位置提供商的设备。

这似乎并不难,但在我看来,我必须组建两个不同的位置提供商(GPS和NETWORK),并管理每个提供商的生命周期。不仅如此,我还必须在多个活动中复制相同的代码以满足#2。过去,我曾尝试使用getBestProvider()将解决方案简化为仅使用一个位置提供程序,但这似乎只提供了最好的“理论”提供程序,而不是实际会为您提供最佳结果的提供程序。

有没有更简单的方法来实现这一点?


当前回答

最近进行了重构以获得代码的位置,学习了一些好的想法,最终实现了一个相对完善的库和演示。

//request all valid provider(network/gps)
private boolean requestAllProviderUpdates() {
    checkRuntimeEnvironment();
    checkPermission();

    if (isRequesting) {
        EasyLog.d("Request location update is busy");
        return false;
    }


    long minTime = getCheckTimeInterval();
    float minDistance = getCheckMinDistance();

    if (mMapLocationListeners == null) {
        mMapLocationListeners = new HashMap<>();
    }

    mValidProviders = getValidProviders();
    if (mValidProviders == null || mValidProviders.isEmpty()) {
        throw new IllegalArgumentException("Not available provider.");
    }

    for (String provider : mValidProviders) {
        LocationListener locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                if (location == null) {
                    EasyLog.e("LocationListener callback location is null.");
                    return;
                }
                printf(location);
                mLastProviderTimestamp = location.getTime();

                if (location.getProvider().equals(LocationManager.GPS_PROVIDER)) {
                    finishResult(location);
                } else {
                    doLocationResult(location);
                }

                removeProvider(location.getProvider());
                if (isEmptyValidProviders()) {
                    requestTimeoutMsgInit();
                    removeUpdates();
                }
            }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {
            }

            @Override
            public void onProviderEnabled(String provider) {
            }

            @Override
            public void onProviderDisabled(String provider) {
            }
        };
        getLocationManager().requestLocationUpdates(provider, minTime, minDistance, locationListener);
        mMapLocationListeners.put(provider, locationListener);
        EasyLog.d("Location request %s provider update.", provider);
    }
    isRequesting = true;
    return true;
}

//remove request update
public void removeUpdates() {
    checkRuntimeEnvironment();

    LocationManager locationManager = getLocationManager();
    if (mMapLocationListeners != null) {
        Set<String> keys = mMapLocationListeners.keySet();
        for (String key : keys) {
            LocationListener locationListener = mMapLocationListeners.get(key);
            if (locationListener != null) {
                locationManager.removeUpdates(locationListener);
                EasyLog.d("Remove location update, provider is " + key);
            }
        }
        mMapLocationListeners.clear();
        isRequesting = false;
    }
}

//Compared with the last successful position, to determine whether you need to filter
private boolean isNeedFilter(Location location) {
    checkLocation(location);

    if (mLastLocation != null) {
        float distance = location.distanceTo(mLastLocation);
        if (distance < getCheckMinDistance()) {
            return true;
        }
        if (location.getAccuracy() >= mLastLocation.getAccuracy()
                && distance < location.getAccuracy()) {
            return true;
        }
        if (location.getTime() <= mLastProviderTimestamp) {
            return true;
        }
    }
    return false;
}

private void doLocationResult(Location location) {
    checkLocation(location);

    if (isNeedFilter(location)) {
        EasyLog.d("location need to filtered out, timestamp is " + location.getTime());
        finishResult(mLastLocation);
    } else {
        finishResult(location);
    }
}

//Return to the finished position
private void finishResult(Location location) {
    checkLocation(location);

    double latitude = location.getLatitude();
    double longitude = location.getLongitude();
    float accuracy = location.getAccuracy();
    long time = location.getTime();
    String provider = location.getProvider();

    if (mLocationResultListeners != null && !mLocationResultListeners.isEmpty()) {
        String format = "Location result:<%f, %f> Accuracy:%f Time:%d Provider:%s";
        EasyLog.i(String.format(format, latitude, longitude, accuracy, time, provider));

        mLastLocation = location;
        synchronized (this) {
            Iterator<LocationResultListener> iterator =  mLocationResultListeners.iterator();
            while (iterator.hasNext()) {
                LocationResultListener listener = iterator.next();
                if (listener != null) {
                    listener.onResult(location);
                }
                iterator.remove();
            }
        }
    }
}

完整代码:https://github.com/bingerz/FastLocation/blob/master/fastlocationlib/src/main/java/cn/bingerz/fastlocation/FastLocation.java

*每次请求完成位置时,最好删除更新,否则手机状态栏将始终显示定位图标。

其他回答

对@Fedor解决方案的改进。我们可以使用位置管理器的requestSingleUpdate方法,而不是使用“0”时间间隔和“0”距离请求位置。更新的代码(kotlin版本)

import android.annotation.SuppressLint
import android.content.Context
import android.location.Criteria
import android.location.Location
import android.location.LocationListener
import android.location.LocationManager
import android.os.Bundle
import java.util.*

@SuppressLint("MissingPermission")
class AppLocationProvider {

  private lateinit var timer: Timer
  private var locationManager: LocationManager? = null
  private lateinit var locationCallBack: LocationCallBack
  private var gpsEnabled = false
  private var networkEnabled = false

  private var locationListener: LocationListener = object : LocationListener {

    override fun onLocationChanged(location: Location) {
      timer.cancel()
      locationCallBack.locationResult(location)
    }

    override fun onProviderDisabled(provider: String) {}
    override fun onProviderEnabled(provider: String) {}
    override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {}
  }

  fun getLocation(context : Context, callBack: LocationCallBack): Boolean {
    locationCallBack = callBack
    if (locationManager == null)
      locationManager = context.getSystemService(Context.LOCATION_SERVICE) as LocationManager?

    //exceptions will be thrown if provider is not permitted.
    try {
      gpsEnabled = locationManager!!.isProviderEnabled(LocationManager.GPS_PROVIDER)
    } catch (ex: Exception) {
      ex.printStackTrace()
    }

    try {
      networkEnabled = locationManager!!.isProviderEnabled(LocationManager.NETWORK_PROVIDER)
    } catch (ex: Exception) {
      ex.printStackTrace()
    }

    //don't start listeners if no provider is enabled
    if (!gpsEnabled && !networkEnabled)
      return false

    val criteria = Criteria()
    if (gpsEnabled) {
      criteria.accuracy = Criteria.ACCURACY_FINE
    } else {
      criteria.accuracy = Criteria.ACCURACY_COARSE
    }
    locationManager!!.requestSingleUpdate(criteria, locationListener, null)

    timer = Timer()
    timer.schedule(GetLastKnownLocation(), 5000)
    return true
  }

  inner class GetLastKnownLocation : TimerTask() {

    override fun run() {
      locationManager!!.removeUpdates(locationListener)

      var netLoc: Location? = null
      var gpsLoc: Location? = null

      if (gpsEnabled)
        gpsLoc = locationManager!!.getLastKnownLocation(LocationManager.GPS_PROVIDER)
      if (networkEnabled)
        netLoc = locationManager!!.getLastKnownLocation(LocationManager.NETWORK_PROVIDER)

      //check which value use the latest one
      if (gpsLoc != null && netLoc != null) {
        if (gpsLoc.time > netLoc.time)
          locationCallBack.locationResult(gpsLoc)
        else
          locationCallBack.locationResult(netLoc)
        return
      }

      if (gpsLoc != null) {
        locationCallBack.locationResult(gpsLoc)
        return
      }
      if (netLoc != null) {
        locationCallBack.locationResult(netLoc)
        return
      }
      locationCallBack.locationResult(null)
    }
  }

  interface LocationCallBack {
    fun locationResult(location: Location?)
  }
}

要获取位置,只需调用getLocation方法-

AppLocationProvider().getLocation(context, object : AppLocationProvider.LocationCallBack {
  override fun locationResult(location: Location?) {
    // use location, this might get called in a different thread if a location is a last known location. In that case, you can post location on main thread
  }
})

注:在调用getLocation方法之前,必须授予所需的位置权限。

通过使用FusedLocationProviderApi,这是最新的API,也是在Android中获取位置的最佳可能性。将其添加到build.gradle文件中

dependencies {
    compile 'com.google.android.gms:play-services:6.5.87'
}

您可以通过此url获取完整的源代码http://javapapers.com/android/android-location-fused-provider/

看到所有答案后,提出问题(最简单、最稳健)。我只点击了图书馆Android ReactiveLocation。

当我制作一个位置跟踪应用程序时。然后我意识到,通过优化电池处理位置跟踪是非常典型的。

所以我想告诉新手和开发者,他们不想在未来的优化中维护他们的位置代码。使用此库。

ReactiveLocationProvider locationProvider = new 

    ReactiveLocationProvider(context);
    locationProvider.getLastKnownLocation()
        .subscribe(new Consumer<Location>() {
            @Override
            public void call(Location location) {
                doSthImportantWithObtainedLocation(location);
            }
        });

要放入应用程序级别build.gradle的依赖项

dependencies {
    ...
    compile 'pl.charmas.android:android-reactive-location2:2.1@aar'
    compile 'com.google.android.gms:play-services-location:11.0.4' //you can use newer GMS version if you need
    compile 'com.google.android.gms:play-services-places:11.0.4'
    compile 'io.reactivex:rxjava:2.0.5' //you can override RxJava version if you need
}

使用此库的优点:

现在和将来都将积极维护这种自由。您不必担心电池优化。因为开发人员已经尽力了。易于安装,放置依赖项和播放。轻松连接到Play Services API获取最后一个已知位置订阅位置更新使用位置设置API管理地理围栏地址列表的地理编码位置活动识别使用当前位置API获取位置自动完成建议

我已经创建了一个小应用程序,并逐步描述以获取当前位置GPS坐标。

以下URL中的完整示例源代码:


获取当前位置坐标,城市名称-在Android中


查看其工作原理:

我们只需要在清单文件中添加此权限<uses permission android:name=“android.permission.ACCESS_FINE_LOCATION”></使用权限>并像这样创建LocationManager实例LocationManager LocationManager=(LocationManager)getSystemService(Context.LOCATION_SERVICE);检查GPS是否已启用然后实现LocationListener和Get CoordinatesLocationListener LocationListener=新的MyLocationListeners();locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,5000,10,locationListener);下面是要做的示例代码


/*----------Listener class to get coordinates ------------- */
private class MyLocationListener implements LocationListener {

    @Override
    public void onLocationChanged(Location loc) {
        editLocation.setText("");
        pb.setVisibility(View.INVISIBLE);
        Toast.makeText(
            getBaseContext(),
            "Location changed: Lat: " + loc.getLatitude() + " Lng: "
                + loc.getLongitude(), Toast.LENGTH_SHORT).show();
        String longitude = "Longitude: " + loc.getLongitude();
        Log.v(TAG, longitude);
        String latitude = "Latitude: " + loc.getLatitude();
        Log.v(TAG, latitude);
        /*-------to get City-Name from coordinates -------- */
        String cityName = null;
        Geocoder gcd = new Geocoder(getBaseContext(), Locale.getDefault());
        List<Address> addresses;
        try {
            addresses = gcd.getFromLocation(loc.getLatitude(),
                loc.getLongitude(), 1);
            if (addresses.size() > 0)
                System.out.println(addresses.get(0).getLocality());
            cityName = addresses.get(0).getLocality();
        } catch (IOException e) {
            e.printStackTrace();
        }
        String s = longitude + "\n" + latitude + "\n\nMy Current City is: "
            + cityName;
        editLocation.setText(s);
    }

    @Override
    public void onProviderDisabled(String provider) {}

    @Override
    public void onProviderEnabled(String provider) {}

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {}
}

Kotlin版本的@Fedor Greate回答:

类的用法:

val locationResult = object : MyLocation.LocationResult() {

    override fun gotLocation(location: Location?) {

        val lat = location!!.latitude
        val lon = location.longitude

        Toast.makeText(context, "$lat --SLocRes-- $lon", Toast.LENGTH_SHORT).show()
    }

}

val myLocation = MyLocation()
myLocation.getLocation(inflater.context, locationResult)

MyLocation类:

class MyLocation {
    internal lateinit var timer1: Timer
    internal var lm: LocationManager? = null
    internal lateinit var locationResult: LocationResult
    internal var gps_enabled = false
    internal var network_enabled = false

    internal var locationListenerGps: LocationListener = object : LocationListener {


        override fun onLocationChanged(location: Location) {
            timer1.cancel()
            locationResult.gotLocation(location)
            lm!!.removeUpdates(this)
            lm!!.removeUpdates(locationListenerNetwork)
        }

        override fun onProviderDisabled(provider: String) {}
        override fun onProviderEnabled(provider: String) {}
        override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {}
    }

    internal var locationListenerNetwork: LocationListener = object : LocationListener {
        override fun onLocationChanged(location: Location) {
            timer1.cancel()
            locationResult.gotLocation(location)
            lm!!.removeUpdates(this)
            lm!!.removeUpdates(locationListenerGps)
        }

        override fun onProviderDisabled(provider: String) {}
        override fun onProviderEnabled(provider: String) {}
        override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {}
    }

    fun getLocation(context: Context, result: LocationResult): Boolean {
        //I use LocationResult callback class to pass location value from MyLocation to user code.
        locationResult = result
        if (lm == null)
            lm = context.getSystemService(Context.LOCATION_SERVICE) as LocationManager?

        //exceptions will be thrown if provider is not permitted.
        try {
            gps_enabled = lm!!.isProviderEnabled(LocationManager.GPS_PROVIDER)
        } catch (ex: Exception) {
        }

        try {
            network_enabled = lm!!.isProviderEnabled(LocationManager.NETWORK_PROVIDER)
        } catch (ex: Exception) {
        }

        //don't start listeners if no provider is enabled
        if (!gps_enabled && !network_enabled)
            return false

        if (ActivityCompat.checkSelfPermission(context,
                Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED ||
            ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) run {

            ActivityCompat.requestPermissions(context as Activity,
                arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION), 111)
        }


        if (gps_enabled)
            lm!!.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0f, locationListenerGps)
        if (network_enabled)
            lm!!.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0f, locationListenerNetwork)
        timer1 = Timer()
        timer1.schedule(GetLastLocation(context), 20000)
        return true
    }

    internal inner class GetLastLocation(var context: Context) : TimerTask() {
        override fun run() {
            lm!!.removeUpdates(locationListenerGps)
            lm!!.removeUpdates(locationListenerNetwork)

            var net_loc: Location? = null
            var gps_loc: Location? = null

            if (ActivityCompat.checkSelfPermission(context,
                    Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED ||
                ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED
            ) run {

                ActivityCompat.requestPermissions(context as Activity,
                    arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION),111)
            }


            if (gps_enabled)
                gps_loc = lm!!.getLastKnownLocation(LocationManager.GPS_PROVIDER)
            if (network_enabled)
                net_loc = lm!!.getLastKnownLocation(LocationManager.NETWORK_PROVIDER)

            //if there are both values use the latest one
            if (gps_loc != null && net_loc != null) {
                if (gps_loc.getTime() > net_loc.getTime())
                    locationResult.gotLocation(gps_loc)
                else
                    locationResult.gotLocation(net_loc)
                return
            }

            if (gps_loc != null) {
                locationResult.gotLocation(gps_loc)
                return
            }
            if (net_loc != null) {
                locationResult.gotLocation(net_loc)
                return
            }
            locationResult.gotLocation(null)
        }
    }

     abstract class LocationResult {
          abstract fun gotLocation(location: Location?)
    }
}